In case e.g. a worker infected with a certain type of respiratory virus is present in an office or the like, there is the risk of infection with the same respiratory virus for the other workers working within the same office. In such case, such infected workers may develop poor physical condition and experience eventual onset of the respiratory organ viral disease, thus leading to significant deterioration in the working efficiency in that office.
Here, the term respiratory virus, is a generic name for various viruses which cause respiratory diseases such as pneumonia in animals. Among them are included influenza virus, parainfluenza virus, rhinovirus, bird flu virus, SARS virus, corona virus, etc. Infection with such respiratory virus and subsequent onset of respiratory virus disease can sometimes result in death of the subject.
Such respiratory viruses exist also in droplets exhaled from a respiratory organ of the infected subject. As the droplets can float in the air, inhalation of droplets containing the respiratory virus leads to spread of the infection and the spread of the respiratory virus.
Incidentally, though not commonly called “respiratory viruses”, measles virus and rubella virus belong in the same category as above because inhalation by an un-infected subject of air contaminated with droplets from a respiratory organ of an infected subject causes secondary infection through the respiratory organ of the former.
For preventing spreading of respiratory virus, one effective measure is eliminating and/or deactivating the respiratory virus floating in the room (in the air). As one example of a method of deactivating respiratory virus floating in a room, there is a method called fumigation (see Non-Patent Document 1).
Non-Patent Document: “Sterilization/Disinfection Manual”, Ishiyaku Publishing Inc. 1991, Sterilization/Disinfection Manual Compiling Committee.